Bacteremia in the pedal circulation following regional intravenous perfusion of a 2% lidocaine solution in cattle with deep digital sepsis

• Autores: Katharine M. Simpson
• Localización: JAVMA: Journal of the American Veterinary Medical Association, ISSN-e 0003-1488, Vol. 245, Nº. 5, 2014, págs. 565-570
• Idioma: inglés
• Texto completo no disponible (Saber más ...)
• Resumen

  • Objective—To evaluate whether pedal bacteremia develops following regional IV perfusion (RIVP) of a 2% lidocaine hydrochloride solution in cattle with deep digital sepsis (DDS) and to determine which bacterial pathogens are most commonly isolated from the pedal circulation.

    Design—Prospective observational cohort study.

    Animals—9 adult cattle with DDS in 10 limbs and 10 healthy adult cattle with no evidence of lameness or digital infection.

    Procedures—Blood samples were obtained aseptically from the dorsal common digital vein immediately following tourniquet application and 30 to 60 minutes after aseptic RIVP with a 2% lidocaine solution. Aerobic and anaerobic bacterial cultures were performed on all samples collected. For cattle with DDS, clinical examination with or without debridement of digital lesions was performed after RIVP.

    Results—Bacteria were isolated from pedal blood prior to RIVP in 1 cow with DDS and after RIVP and examination with or without debridement in that cow and 4 additional cattle with DDS. Bacteria were not isolated from any blood sample obtained from the healthy cattle. Of the 8 bacterial isolates identified, 5 were gram-positive facultative anaerobes. Cattle with DDS were significantly more likely to develop bacteremia in the pedal circulation than were healthy cattle following RIVP.

    Conclusions and Clinical Relevance—Results indicated that bacteremia may be present in the pedal circulation before and following RIVP and examination with or without debridement in cattle with DDS. Thus, systemic or local antimicrobial treatment might be warranted prior to or concurrently with RIVP in cattle with DDS.

    In cattle, DDS develops when the septic process associated with digital infections extends locally to the phalanges, navicular bone, synovial structures, or flexor tendons.1–3 A variety of common causes of lameness can initiate DDS and result in infection and necrosis of essential weight-bearing digital structures.1,2,4–8 Surgical treatment of DDS is warranted unless the affected animal is immediately slaughtered or euthanized and typically involves local debridement to remove devitalized tissues and establish drainage or amputation of the affected digit in salvage animals.1,7,9 Because such treatments are very painful, RIVP of local anesthetic solutions is often used to provide analgesia. Additionally, RIVP of antimicrobials is an effective adjunctive treatment for infections of the distal aspect of the limb.10–15 Dissemination of bacteria from distal sites of infection has been reported following RIVP in both human and veterinary patients. In 1 study,16 4 of 15 human patients undergoing treatment for osteomyelitis developed signs of systemic sepsis within 4 hours after RIVP, and 1 patient was bacteremic, which resulted in a recommendation that patients be administered systemic antimicrobials prior to initiation of RIVP. In foals with septic tibiotarsal joints, secondary septic foci have been detected in the affected limbs after RIVP with antimicrobials.17 Caudal vena caval thrombosis was detected in a Holstein cow following multiple RIVPs and treatment of DDS, despite the absence of evidence of hepatic abscesses or another source of sepsis during necropsy.18 It is possible that the use of RIVP in cattle with DDS might cause local or systemic dissemination of bacterial pathogens, and the potential for development of bacteremia following a common treatment modality in cattle warrants investigation.

    The objectives of the study reported here were to determine whether bacteremia of the pedal circulation develops following RIVP of a 2% lidocaine solution administered for examination with or without debridement of digital lesions in cattle with DDS and, if so, to determine which bacterial pathogens are most commonly isolated from the pedal circulation. We hypothesized that the probability of the detection of bacteremia in the pedal circulation of cattle with DDS following RIVP would be 25%, which we extrapolated from data regarding the likelihood of detecting bacteremia in the systemic circulation of neonatal patients with clinical sepsis.19 We also hypothesized that the most common bacteria isolated from the pedal circulation of cattle with DDS would be gram-negative anaerobes because those microorganisms are frequently associated with digital disease in cattle.20